- #1
PiRsq
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The question asked me to find the head of a vector [a,b,c] whose length is 3 and is in the same direction as vector
a=[-3,-4,12]
So I found the follwing:
Let vector x be the unknown vector
|a|=13
|x|=3
Since they are both in the same direction, they both must have the same direction angles right?
So:
Cos alpha = -3/13 which is equal to a/3
Cos beta = -4/13 which is equal to b/3
Cos gamma = 12/13 which is equal to c/3
Then I got the values for a,b and c but the book shows me a different answer. What am I doing wrong here?
a=[-3,-4,12]
So I found the follwing:
Let vector x be the unknown vector
|a|=13
|x|=3
Since they are both in the same direction, they both must have the same direction angles right?
So:
Cos alpha = -3/13 which is equal to a/3
Cos beta = -4/13 which is equal to b/3
Cos gamma = 12/13 which is equal to c/3
Then I got the values for a,b and c but the book shows me a different answer. What am I doing wrong here?